/*
*********************************************************************************************************
*                                                uC/OS-II
*                                          The Real-Time Kernel
*                                       MESSAGE MAILBOX MANAGEMENT
*
*                          (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
*                                           All Rights Reserved
*
* File : OS_MBOX.C
* By   : Jean J. Labrosse
*********************************************************************************************************
*/

#ifndef  OS_MASTER_FILE
#include "includes.h"
#endif

#if OS_MBOX_EN > 0
/*
*********************************************************************************************************
*                                     ACCEPT MESSAGE FROM MAILBOX
*
* Description: This function checks the mailbox to see if a message is available.  Unlike OSMboxPend(),
*              OSMboxAccept() does not suspend the calling task if a message is not available.
*
* Arguments  : pevent        is a pointer to the event control block
*
* Returns    : != (void *)0  is the message in the mailbox if one is available.  The mailbox is cleared
*                            so the next time OSMboxAccept() is called, the mailbox will be empty.
*              == (void *)0  if the mailbox is empty or,
*                            if 'pevent' is a NULL pointer or,
*                            if you didn't pass the proper event pointer.
*********************************************************************************************************
*/

#if OS_MBOX_ACCEPT_EN > 0
//checks the mailbox to see if a message is available.
//任务在请求邮箱失败也可以不进行等待二继续运行 则调用此函数
void  *OSMboxAccept (OS_EVENT *pevent)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif    
    void      *msg;

#if OS_ARG_CHK_EN > 0
    if (pevent == (OS_EVENT *)0) {                        /* Validate 'pevent'                         */
        return ((void *)0);
    }
    if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) {      /* Validate event block type                 */
        return ((void *)0);
    }
#endif
    OS_ENTER_CRITICAL();
    msg                = pevent->OSEventPtr;
    pevent->OSEventPtr = (void *)0;                       /* Clear the mailbox                         */
    OS_EXIT_CRITICAL();
    return (msg);                                         /* Return the message received (or NULL)     */
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                        CREATE A MESSAGE MAILBOX
*
* Description: This function creates a message mailbox if free event control blocks are available.
*
* Arguments  : msg           is a pointer to a message that you wish to deposit in the mailbox.  If
*                            you set this value to the NULL pointer (i.e. (void *)0) then the mailbox
*                            will be considered empty.
*
* Returns    : != (OS_EVENT *)0  is a pointer to the event control clock (OS_EVENT) associated with the
*                                created mailbox
*              == (OS_EVENT *)0  if no event control blocks were available
*********************************************************************************************************
*/
//This function creates a message mailbox if free event control blocks are available.
OS_EVENT  *OSMboxCreate (void *msg)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif    
    OS_EVENT  *pevent;

    
    if (OSIntNesting > 0) {                      /* See if called from ISR ...                         */
        return ((OS_EVENT *)0);                  /* ... can't CREATE from an ISR                       */
    }
    OS_ENTER_CRITICAL();
    //Get next free event control block
    pevent = OSEventFreeList;                    /* Get next free event control block                  */
    if (OSEventFreeList != (OS_EVENT *)0) {      /* See if pool of free ECB pool was empty             */
        OSEventFreeList = (OS_EVENT *)OSEventFreeList->OSEventPtr;
    }
    OS_EXIT_CRITICAL();
    //创建邮箱
    if (pevent != (OS_EVENT *)0) {
        pevent->OSEventType = OS_EVENT_TYPE_MBOX;
        pevent->OSEventCnt  = 0;
        //msg指向消息邮箱缓冲区
        pevent->OSEventPtr  = msg;               /* Deposit message in event control block             */
        OS_EventWaitListInit(pevent);
    }
    return (pevent);                             /* Return pointer to event control block              */
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                         DELETE A MAIBOX
*
* Description: This function deletes a mailbox and readies all tasks pending on the mailbox.
*
* Arguments  : pevent        is a pointer to the event control block associated with the desired
*                            mailbox.
*
*              opt           determines delete options as follows:
*                            opt == OS_DEL_NO_PEND   Delete the mailbox ONLY if no task pending
*                            opt == OS_DEL_ALWAYS    Deletes the mailbox even if tasks are waiting.
*                                                    In this case, all the tasks pending will be readied.
*
*              err           is a pointer to an error code that can contain one of the following values:
*                            OS_NO_ERR               The call was successful and the mailbox was deleted
*                            OS_ERR_DEL_ISR          If you attempted to delete the mailbox from an ISR
*                            OS_ERR_INVALID_OPT      An invalid option was specified
*                            OS_ERR_TASK_WAITING     One or more tasks were waiting on the mailbox
*                            OS_ERR_EVENT_TYPE       If you didn't pass a pointer to a mailbox
*                            OS_ERR_PEVENT_NULL      If 'pevent' is a NULL pointer.
*
* Returns    : pevent        upon error
*              (OS_EVENT *)0 if the mailbox was successfully deleted.
*
* Note(s)    : 1) This function must be used with care.  Tasks that would normally expect the presence of
*                 the mailbox MUST check the return code of OSMboxPend().
*              2) OSMboxAccept() callers will not know that the intended mailbox has been deleted!
*              3) This call can potentially disable interrupts for a long time.  The interrupt disable
*                 time is directly proportional to the number of tasks waiting on the mailbox.
*              4) Because ALL tasks pending on the mailbox will be readied, you MUST be careful in
*                 applications where the mailbox is used for mutual exclusion because the resource(s)
*                 will no longer be guarded by the mailbox.
*********************************************************************************************************
*/

#if OS_MBOX_DEL_EN > 0
//This function deletes a mailbox and readies all tasks pending on the mailbox.
OS_EVENT  *OSMboxDel (OS_EVENT *pevent, INT8U opt, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3                                /* Allocate storage for CPU status register */
    OS_CPU_SR  cpu_sr;
#endif    
    BOOLEAN    tasks_waiting;

    //各种判断
    if (OSIntNesting > 0) {                                /* See if called from ISR ...               */
        *err = OS_ERR_DEL_ISR;                             /* ... can't DELETE from an ISR             */
        return (pevent);
    }
#if OS_ARG_CHK_EN > 0
    if (pevent == (OS_EVENT *)0) {                         /* Validate 'pevent'                        */
        *err = OS_ERR_PEVENT_NULL;
        return (pevent);
    }
    if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) {       /* Validate event block type                */
        *err = OS_ERR_EVENT_TYPE;
        return (pevent);
    }
#endif
    OS_ENTER_CRITICAL();
    if (pevent->OSEventGrp != 0x00) {                      /* See if any tasks waiting on mailbox      */
        tasks_waiting = TRUE;                              /* Yes                                      */
    } else {
        tasks_waiting = FALSE;                             /* No                                       */
    }
    switch (opt) {
        //Delete mailbox only if no task waiting  
        case OS_DEL_NO_PEND:                               /* Delete mailbox only if no task waiting   */
             if (tasks_waiting == FALSE) {
                 pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
                 pevent->OSEventPtr  = OSEventFreeList;    /* Return Event Control Block to free list  */
                 OSEventFreeList     = pevent;             /* Get next free event control block        */
                 OS_EXIT_CRITICAL();
                 *err = OS_NO_ERR;
                 return ((OS_EVENT *)0);                   /* Mailbox has been deleted                 */
             } else {
                 OS_EXIT_CRITICAL();
                 *err = OS_ERR_TASK_WAITING;
                 return (pevent);
             }
        //Always delete the mailbox  
        case OS_DEL_ALWAYS:                                /* Always delete the mailbox                */
             while (pevent->OSEventGrp != 0x00) {          /* Ready ALL tasks waiting for mailbox      */
                 OS_EventTaskRdy(pevent, (void *)0, OS_STAT_MBOX);
             }
             pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
             pevent->OSEventPtr  = OSEventFreeList;        /* Return Event Control Block to free list  */
             OSEventFreeList     = pevent;                 /* Get next free event control block        */
             OS_EXIT_CRITICAL();
            //Reschedule only if task(s) were waiting
             if (tasks_waiting == TRUE) {                  /* Reschedule only if task(s) were waiting  */
                 OS_Sched();                               /* Find highest priority task ready to run  */
             }
             *err = OS_NO_ERR;
             return ((OS_EVENT *)0);                       /* Mailbox has been deleted                 */

        default:
             OS_EXIT_CRITICAL();
             *err = OS_ERR_INVALID_OPT;
             return (pevent);
    }
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                      PEND ON MAILBOX FOR A MESSAGE
*
* Description: This function waits for a message to be sent to a mailbox
*
* Arguments  : pevent        is a pointer to the event control block associated with the desired mailbox
*
*              timeout       is an optional timeout period (in clock ticks).  If non-zero, your task will
*                            wait for a message to arrive at the mailbox up to the amount of time
*                            specified by this argument.  If you specify 0, however, your task will wait
*                            forever at the specified mailbox or, until a message arrives.
*
*              err           is a pointer to where an error message will be deposited.  Possible error
*                            messages are:
*
*                            OS_NO_ERR           The call was successful and your task received a
*                                                message.
*                            OS_TIMEOUT          A message was not received within the specified timeout
*                            OS_ERR_EVENT_TYPE   Invalid event type
*                            OS_ERR_PEND_ISR     If you called this function from an ISR and the result
*                                                would lead to a suspension.
*                            OS_ERR_PEVENT_NULL  If 'pevent' is a NULL pointer
*
* Returns    : != (void *)0  is a pointer to the message received
*              == (void *)0  if no message was received or,
*                            if 'pevent' is a NULL pointer or,
*                            if you didn't pass the proper pointer to the event control block.
*********************************************************************************************************
*/
// This function waits for a message to be sent to a mailbox
void  *OSMboxPend (OS_EVENT *pevent, INT16U timeout, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif    
    void      *msg;

    //各种判断
    if (OSIntNesting > 0) {                           /* See if called from ISR ...                    */
        *err = OS_ERR_PEND_ISR;                       /* ... can't PEND from an ISR                    */
        return ((void *)0);
    }
#if OS_ARG_CHK_EN > 0
    if (pevent == (OS_EVENT *)0) {                    /* Validate 'pevent'                             */
        *err = OS_ERR_PEVENT_NULL;
        return ((void *)0);
    }
    if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) {  /* Validate event block type                     */
        *err = OS_ERR_EVENT_TYPE;
        return ((void *)0);
    }
#endif
    OS_ENTER_CRITICAL();
    msg = pevent->OSEventPtr;
    if (msg != (void *)0) {                           /* See if there is already a message             */
        pevent->OSEventPtr = (void *)0;               /* Clear the mailbox                             */
        OS_EXIT_CRITICAL();
        *err = OS_NO_ERR;
        return (msg);                                 /* Return the message received (or NULL)         */
    }
    //Message not available, task will pend  
    OSTCBCur->OSTCBStat |= OS_STAT_MBOX;              /* Message not available, task will pend         */
    OSTCBCur->OSTCBDly   = timeout;                   /* Load timeout in TCB                           */
    //Suspend task until event or timeout occurs
    OS_EventTaskWait(pevent);                         /* Suspend task until event or timeout occurs    */
    OS_EXIT_CRITICAL();
    OS_Sched();                                       /* Find next highest priority task ready to run  */
    OS_ENTER_CRITICAL();
    msg = OSTCBCur->OSTCBMsg;
    if (msg != (void *)0) {                           /* See if we were given the message              */
        OSTCBCur->OSTCBMsg      = (void *)0;          /* Yes, clear message received                   */
        OSTCBCur->OSTCBStat     = OS_STAT_RDY;
        OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0;      /* No longer waiting for event                   */
        OS_EXIT_CRITICAL();
        *err                    = OS_NO_ERR;
        return (msg);                                 /* Return the message received                   */
    }
    // Timed out, Make task ready   
    OS_EventTO(pevent);                               /* Timed out, Make task ready                    */
    OS_EXIT_CRITICAL();
    *err = OS_TIMEOUT;                                /* Indicate that a timeout occured               */
    return ((void *)0);                               /* Return a NULL message                         */
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                       POST MESSAGE TO A MAILBOX
*
* Description: This function sends a message to a mailbox
*
* Arguments  : pevent        is a pointer to the event control block associated with the desired mailbox
*
*              msg           is a pointer to the message to send.  You MUST NOT send a NULL pointer.
*
* Returns    : OS_NO_ERR            The call was successful and the message was sent
*              OS_MBOX_FULL         If the mailbox already contains a message.  You can can only send one
*                                   message at a time and thus, the message MUST be consumed before you
*                                   are allowed to send another one.
*              OS_ERR_EVENT_TYPE    If you are attempting to post to a non mailbox.
*              OS_ERR_PEVENT_NULL   If 'pevent' is a NULL pointer
*              OS_ERR_POST_NULL_PTR If you are attempting to post a NULL pointer
*********************************************************************************************************
*/

#if OS_MBOX_POST_EN > 0
//This function sends a message to a mailbox
INT8U  OSMboxPost (OS_EVENT *pevent, void *msg)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif    
    
    
#if OS_ARG_CHK_EN > 0
    if (pevent == (OS_EVENT *)0) {                    /* Validate 'pevent'                             */
        return (OS_ERR_PEVENT_NULL);
    }
    if (msg == (void *)0) {                           /* Make sure we are not posting a NULL pointer   */
        return (OS_ERR_POST_NULL_PTR);
    }
    if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) {  /* Validate event block type                     */
        return (OS_ERR_EVENT_TYPE);
    }
#endif
    OS_ENTER_CRITICAL();
    if (pevent->OSEventGrp != 0x00) {                 /* See if any task pending on mailbox            */
        OS_EventTaskRdy(pevent, msg, OS_STAT_MBOX);   /* Ready highest priority task waiting on event  */
        OS_EXIT_CRITICAL();
        OS_Sched();                                   /* Find highest priority task ready to run       */
        return (OS_NO_ERR);
    }
    if (pevent->OSEventPtr != (void *)0) {            /* Make sure mailbox doesn't already have a msg  */
        OS_EXIT_CRITICAL();
        return (OS_MBOX_FULL);
    }
    pevent->OSEventPtr = msg;                         /* Place message in mailbox                      */
    OS_EXIT_CRITICAL();
    return (OS_NO_ERR);
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                       POST MESSAGE TO A MAILBOX
*
* Description: This function sends a message to a mailbox
*
* Arguments  : pevent        is a pointer to the event control block associated with the desired mailbox
*
*              msg           is a pointer to the message to send.  You MUST NOT send a NULL pointer.
*
*              opt           determines the type of POST performed:
*                            OS_POST_OPT_NONE         POST to a single waiting task
*                                                     (Identical to OSMboxPost())
*                            OS_POST_OPT_BROADCAST    POST to ALL tasks that are waiting on the mailbox
*
* Returns    : OS_NO_ERR            The call was successful and the message was sent
*              OS_MBOX_FULL         If the mailbox already contains a message.  You can can only send one
*                                   message at a time and thus, the message MUST be consumed before you
*                                   are allowed to send another one.
*              OS_ERR_EVENT_TYPE    If you are attempting to post to a non mailbox.
*              OS_ERR_PEVENT_NULL   If 'pevent' is a NULL pointer
*              OS_ERR_POST_NULL_PTR If you are attempting to post a NULL pointer
*
* Warning    : Interrupts can be disabled for a long time if you do a 'broadcast'.  In fact, the
*              interrupt disable time is proportional to the number of tasks waiting on the mailbox.
*********************************************************************************************************
*/

#if OS_MBOX_POST_OPT_EN > 0
//This function sends a message to a mailbox  这函数可以以广播的形式发送一个邮箱信息
INT8U  OSMboxPostOpt (OS_EVENT *pevent, void *msg, INT8U opt)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif    
    
    //各种验证判断
#if OS_ARG_CHK_EN > 0
    if (pevent == (OS_EVENT *)0) {                    /* Validate 'pevent'                             */
        return (OS_ERR_PEVENT_NULL);
    }
    if (msg == (void *)0) {                           /* Make sure we are not posting a NULL pointer   */
        return (OS_ERR_POST_NULL_PTR);
    }
    if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) {  /* Validate event block type                     */
        return (OS_ERR_EVENT_TYPE);
    }
#endif
    OS_ENTER_CRITICAL();
    if (pevent->OSEventGrp != 0x00) {                 /* See if any task pending on mailbox            */
        // Do we need to post msg to ALL waiting tasks
        if ((opt & OS_POST_OPT_BROADCAST) != 0x00) {  /* Do we need to post msg to ALL waiting tasks ? */
            while (pevent->OSEventGrp != 0x00) {      /* Yes, Post to ALL tasks waiting on mailbox     */           
                OS_EventTaskRdy(pevent, msg, OS_STAT_MBOX);    
            }
        } else {
        // Find highest priority task ready to run 否则就发送最高优先级的信息
            OS_EventTaskRdy(pevent, msg, OS_STAT_MBOX);    /* No,  Post to HPT waiting on mbox         */
        }
        OS_EXIT_CRITICAL();
        OS_Sched();                                        /* Find highest priority task ready to run  */
        return (OS_NO_ERR);
    }
    if (pevent->OSEventPtr != (void *)0) {            /* Make sure mailbox doesn't already have a msg  */
        OS_EXIT_CRITICAL();
        return (OS_MBOX_FULL);
    }
    pevent->OSEventPtr = msg;                         /* Place/放置 message in mailbox                      */
    OS_EXIT_CRITICAL();
    return (OS_NO_ERR);
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                        QUERY A MESSAGE MAILBOX
*
* Description: This function obtains information about a message mailbox.
*
* Arguments  : pevent        is a pointer to the event control block associated with the desired mailbox
*
*              pdata         is a pointer to a structure that will contain information about the message
*                            mailbox.
*
* Returns    : OS_NO_ERR           The call was successful and the message was sent
*              OS_ERR_EVENT_TYPE   If you are attempting to obtain data from a non mailbox.
*              OS_ERR_PEVENT_NULL  If 'pevent' is a NULL pointer
*********************************************************************************************************
*/

#if OS_MBOX_QUERY_EN > 0
//This function obtains information about a message mailbox.
INT8U  OSMboxQuery (OS_EVENT *pevent, OS_MBOX_DATA *pdata)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif    
    INT8U     *psrc;
    INT8U     *pdest;

#if OS_ARG_CHK_EN > 0
    //验证
    if (pevent == (OS_EVENT *)0) {                         /* Validate 'pevent'                        */
        return (OS_ERR_PEVENT_NULL);
    }
    if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) {       /* Validate event block type                */
        return (OS_ERR_EVENT_TYPE);
    }
#endif
    OS_ENTER_CRITICAL();
    // Copy message mailbox wait list  
    pdata->OSEventGrp = pevent->OSEventGrp;                /* Copy message mailbox wait list           */
    psrc              = &pevent->OSEventTbl[0];
    pdest             = &pdata->OSEventTbl[0];

#if OS_EVENT_TBL_SIZE > 0
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 1
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 2
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 3
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 4
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 5
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 6
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 7
    *pdest            = *psrc;
#endif
    pdata->OSMsg = pevent->OSEventPtr;                     /* Get message from mailbox                 */
    OS_EXIT_CRITICAL();
    return (OS_NO_ERR);
}
#endif                                                     /* OS_MBOX_QUERY_EN                         */
#endif                                                     /* OS_MBOX_EN                               */

uC/OS-II邮箱(mbox)块的更多相关文章

  1. uC/OS II原理分析及源码阅读(一)

    uC/OS II(Micro Control Operation System Two)是一个可以基于ROM运行的.可裁减的.抢占式.实时多任务内核,具有高度可移植性,特别适合于微处理器和控制器,是和 ...

  2. 【原创】uC/OS II 任务切换原理

    今天学习了uC/OS II的任务切换,知道要实现任务的切换,要将原先任务的寄存器压入任务堆栈,再将新任务中任务堆栈的寄存器内容弹出到CPU的寄存器,其中的CS.IP寄存器没有出栈和入栈指令,所以只能引 ...

  3. 【小梅哥SOPC学习笔记】NIOS II处理器运行UC/OS II

    SOPC开发流程之NIOS II 处理器运行 UC/OS II 这里以在芯航线FPGA学习套件的核心板上搭建 NIOS II 软核并运行 UCOS II操作系统为例介绍SOPC的开发流程. 第一步:建 ...

  4. uC/OS II 函数说明 之–OSTaskCreate()与OSTaskCreateExt()

    1. OSTaskCreate()    OSTaskCreate()建立一个新任务,能够在多任务环境启动之前,或者执行任务中建立任务.注意,ISR中禁止建立任务,一个任务必须为无限循环结构.    ...

  5. uc/os iii移植到STM32F4---IAR开发环境

    也许是先入为主的原因,时钟用不惯Keil环境,大多数的教程都是拿keil写的,尝试将官方的uc/os iii 移植到IAR环境. 1.首先尝试从官网上下载的官方移植的代码,编译通过,但是执行会报堆栈溢 ...

  6. uc/os 任务删除

    问题描述:     uc/os 任务删除 问题解决: uc/os任务删除流程图 具体代码 注:     如上是关中断,以及取消优先级对应的就绪标志 关中断代码为: 取消就绪标志,实际上是将就绪表中指定 ...

  7. uc/os任务创建

    问题描述:      uc/os中任务创建 问题解决: 创建一个任务,任务从无到有.任务创建函数分两种, 一种是基本的创建函数OSTaskCreate, 另一种是扩展的任务创建函数OSTaskCrea ...

  8. uC/OS 的任务调度解析 (转)

    uC/OS 的任务调度解析 1.任务调度器启动之后(初始化,主要是TCB的初始化),就可以创建任务,开始任务调度了,实际上第一个任务准确的说不是进行任务切换,而是进行启动当前最高优先级任务.uC/OS ...

  9. 关于uC/OS的简单学习(转)

    1.微内核 与Linux的首要区别是,它是一个微内核,内核所实现的功能非常简单,主要包括: 一些通用函数,如TaskCreate(),OSMutexPend(),OSQPost()等. 中断处理函数, ...

随机推荐

  1. 富文本KidnEditor在MVC中的应用

    最近看到很多网站后台都用到了富文本,包括自己所在的公司也是.公司用的KindEditor,所以就讲讲KindEditor.之前我也没学过,所以网上搜了一篇博文,直接转载如下(PS:完全以学习为目的哦~ ...

  2. hihocoder1241 Best Route in a Grid

    题目链接:hihocoder 1241 题意: n*n的格阵,每个方格内有一个数字.蚂蚁从左上角走到右下角,数字是零的方格不能走,只能向右向下走.蚂蚁走的路径上全部方格的的乘积为s,要使s低位0的个数 ...

  3. 曾经post为何只能通过form来提交

    当我们web程序的前台,需要有数据向后台发送时候,我们第一时间想到的就是,给我们所需要提交的用户名,密码之类的数据封装到一个<form>表单里面去,而封装完毕之后,我们需要给form的提交 ...

  4. C# 对sharepoint 列表的一些基本操作,包括添加/删除/查询/上传文件给sharepoint list添加数据

    转载:http://www.cnblogs.com/kivenhou/archive/2013/02/22/2921954.html 操作List前请设置SPWeb的allowUnsafeUpdate ...

  5. C# Label显示多行文本及换行(WinForm/WebForm)

    转载: http://www.cnblogs.com/greatverve/archive/2011/10/20/label-multi.html WinForm 很多朋友都会在开发WinForm中遇 ...

  6. The hierarchy of the type NsRedisConnectionFactory is inconsistent

    The hierarchy of the type is inconsistent 解释为:层次结构的类型不一致 由于我在eclipse里建了两个JAVA PROJECT项目,分别是A projiec ...

  7. python 中的sort 和java中的Collections.sort()函数的使用

    x=[1,2,3] x.sort()对的,x这个都变了 y=x.sort()错误 y=sorted(x)对的,x拍好序的一个副本 python中用匿名函数和自定义函数排序:(很奇怪的是比较函数返回的是 ...

  8. git初体验(四)git标签

    1.git 标题(tag) 关于git标签的描述,参考这里 2.标题管理 创建: 切换到需要打标签的分支上,如: git checkout master git tag v1.0 # 默认标签是打在最 ...

  9. java基础3.0:Java常用API

    本篇介绍Java基础中常用API使用,当然只是简单介绍,围绕重要知识点引入,巩固开发知识,深入了解每个API的使用,查看JavaAPI文档是必不可少的. 一.java.lang包下的API Java常 ...

  10. dede使用方法----如何去掉dede自带的版权

    最近有朋友问如何将dede的Power by DedeCms去掉,一来为了安全,二来外链确实有些影响,这里分享下去除方法,需要的朋友可以参考下   自从dedecms织梦系统更新到6.7日的版本,底部 ...